JP2008082468A - Air spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air spring for preventing reduction in the service life of a diaphragm. <P>SOLUTION: A sleeve member 60 is formed in a substantially cylindrical shape, and is formed in a larger diameter than the diaphragm 32. One end 60A of the sleeve member 60 is arranged outside an upper side caulking ring 42, and engages the upper side caulking ring 42 with an inner peripheral side recessed part. The other end 60B of the sleeve 60 is arranged in the vicinity of a U-shaped part 34 of the diaphragm 32 at neutral time, and an opening part 60K is constituted inside the other end 60B. The other end 60B is curved outside in the radial direction, and the diaphragm 32 side is formed in a round shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air spring that generates an elastic reaction force against an input load using air pressure and supports the input load by the reaction force.

  As an air spring used for a vehicle suspension or the like, for example, one described in Patent Document 1 is known. The air spring described in Patent Document 1 includes a diaphragm of an air suspension and a bellows-like cover that covers the diaphragm from the outside. An intermediate cover is provided between the upper part of the bellows-like cover and the diaphragm, and the diaphragm is not continuously rubbed by the bellows-like cover by the intermediate cover, so that the lifetime of the diaphragm is prevented from being reduced. In particular, a diaphragm for a passenger car is a thin film compared to a railway vehicle and a bus / truck, and therefore has a low durability due to rubbing or the like. Therefore, it is preferable to attach an intermediate cover.

In the above configuration, the diaphragm and the intermediate cover are in contact with each other, and according to Patent Document 1, the intermediate cover is sized so as not to cover the U-turn portion of the diaphragm in the most separated state between the wheel and the vehicle. Yes. Therefore, it is considered that the tip of the intermediate cover and the diaphragm rub against each other during rebound, and the diaphragm is worn.
JP 2004-34871 A

  The present invention has been made in view of the above-described facts, and an object thereof is to provide an air spring in which the life of the diaphragm is prevented from being lowered.

  In order to achieve the above object, an air spring according to claim 1 of the present invention is an air spring disposed between a first moving body and a second moving body that move relative to each other, and is on the first moving body side. A chamber member attached to the second moving body, a cylindrical member attached to the second moving body side, one end connected to the chamber member and the other end connected to the piston member, and a chamber chamber inside The other end portion having a smaller diameter than the intermediate portion is a diaphragm that is folded back into the cylinder with the intermediate portion in the inside / outside inverted state, one end is attached to the first moving body side, and the other end is opened, A cylindrical sleeve member that covers the outer periphery of the diaphragm, and a friction reducing portion that reduces friction with the diaphragm is formed at the other end of the sleeve member.

  The air spring of the present invention is disposed between a first moving body and a second moving body that move relative to each other. The first moving body and the second moving body here may be any one as long as at least one moves and moves relative to each other, and one of them may not be moved.

  The chamber member is attached to the first moving body side, and the piston member is attached to the second moving body side. Each of the chamber member and the piston member may be directly attached to the first moving body and the second moving body, or may be indirectly attached via another member.

  The diaphragm is cylindrical and has one end connected to the chamber member and the other end connected to the piston member to form a chamber chamber inside. The other end portion has a smaller diameter than the intermediate portion, and the other end portion is folded back into the cylinder. As a result, the intermediate portion is in an inverted state.

  The sleeve member has one end attached to the first moving body and the other end opened. Moreover, the outer periphery of the diaphragm is covered. At the other end of the sleeve member, a friction reducing portion for reducing friction with the diaphragm is formed. Therefore, rubbing between the other end of the sleeve member and the diaphragm, in particular, wear due to rubbing during rebounding can be reduced, and shortening of the diaphragm life can be suppressed.

  An air spring according to a second aspect of the present invention is characterized in that the friction reducing portion is formed by bending the other end of the sleeve member outward.

  In this way, by curving the other end of the sleeve member outward, the contact portion with the diaphragm becomes an R shape, so that wear due to rubbing with the diaphragm can be reduced.

  An air spring according to a third aspect of the present invention is characterized in that the friction reducing portion is formed with the other end of the sleeve member having a rounded corner.

  In this way, wear due to rubbing with the diaphragm can be reduced by rounding the other end of the sleeve member.

  An air spring according to a fourth aspect of the present invention is characterized in that the friction reducing portion is formed by attaching a rounded corner cover to the other end of the sleeve member.

  Thus, by attaching a rounded corner cover to the other end of the sleeve member, wear due to rubbing with the diaphragm can be reduced.

  As described above, according to the air spring of the present invention, it is possible to prevent the life of the diaphragm from being lowered.

  Hereinafter, an air spring according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows a suspension to which an air spring according to an embodiment of the present invention is applied. The air spring of this embodiment is disposed between the vehicle body as the first moving body and the suspension arm as the second moving body. As shown in FIG. 1, the suspension 12 includes an air spring 10 formed in a drum shape as a whole and a suspension arm 14 formed in a beam shape. Cylindrical bush holders 16 and 18 are disposed on the suspension arm 14 at the proximal end and the distal end along the longitudinal direction, respectively. In FIG. 1, the suspension arm 14 is disposed at a neutral position.

  The suspension arm 14 is connected to a vehicle body 15 side via a rubber bush (not shown) so that a base end side bush holder 16 is swingable, and a distal end side bush holder 18 is connected to a wheel hub (not shown). (Omitted) It is rotatably connected to the side. Thus, the suspension arm 14 is supported by the vehicle body 15 so as to be swingable in the vertical direction around the bush holder 16 on the base end side.

  As shown in FIG. 1, the air spring 10 is provided with a piston member 24 formed in a substantially bottomed cylindrical shape at the lower end side, and a chamber member 22 is disposed above the piston member 24.

  The piston member 24 is integrally formed with a cylindrical connected portion 28 whose inner and outer diameters are reduced with respect to the lower end side at the upper end portion. The piston member 24 is fixed to the bracket 26 on the bottom plate lower surface side. The bracket 26 has a shallow dish shape and is fixed to the suspension arm 14 with bolts or the like.

  The chamber member 22 has a bottomed cylindrical shape and is fixed to the vehicle body 15 with the bottom portion 22A on the top surface. In the chamber member 22, a cylindrical connected portion 22B is bent and formed so as to protrude downward from the outer peripheral end portion of the bottom portion 22A.

  The air spring 10 is provided with a diaphragm 32. The diaphragm 32 has a thin cylindrical shape, one end portion 32 </ b> A is connected to the connected portion 28 of the piston member 24, and the other end portion 32 </ b> B is connected to the connected portion 22 </ b> B of the chamber member 22. The diaphragm 32 is formed of a rubber film, and a U-shaped portion 34 is formed at an intermediate portion. The other end 32B has a smaller diameter than the U-shaped portion 34. The diaphragm 32 is folded at the U-shaped portion 34 so that the other end portion 32B side enters the cylinder, and the inner peripheral surface and the outer peripheral surface are reversed.

  One end portion 32A of the diaphragm 32 is formed in a cylindrical shape and is fitted and inserted so as to cover the outer periphery of the connected portion 22B. The other end 32B is also formed in a cylindrical shape, and is fitted and inserted so as to cover the outer periphery of the connected portion 28.

  The air spring 10 includes a lower caulking ring 29 that is wound around the outer peripheral side of the other end portion 32B, and an upper caulking ring 42 that is wound around the outer peripheral side of the one end portion 32A. The lower caulking ring 29 is configured so that the other end portion 32B is tightened to the inner peripheral side and pressed to the outer peripheral surface of the coupled portion 28 over the entire circumference, and the other end portion 32B is airtight to the coupled portion 28. It is connected and fixed. Further, the upper caulking ring 42 is fastened with one end portion 32A to the inner peripheral side and press-contacted to the outer peripheral surface of the coupled portion 22B over the entire circumference, and is connected and fixed so that the one end portion 32A is airtight with the coupled portion 22B. is doing. Thereby, a substantially cylindrical chamber chamber 44 is formed on the inner peripheral side of the diaphragm 32.

  As shown in FIG. 1, the chamber member 22 is fixed at a position facing the piston member 24 on the vehicle body 15 side. Thereby, the air spring 10 is interposed between the suspension arm 14 and the vehicle body 15. One end of a pressure pipe 46 is connected to the top plate portion of the chamber member 22. The other end of the pressure pipe 46 is connected to a compressed air supply source (not shown) such as an air pump or an accumulator mounted on the vehicle body 15 side, and the compressed air supply source communicates with the chamber chamber 44. Yes. The pressure air supply source supplies compressed air having an air pressure corresponding to the traveling state of the vehicle and the loaded load into the chamber 44 through the pressure pipe 46.

  The air spring 10 is provided with a sleeve member 60. The sleeve member 60 is substantially cylindrical and has a larger diameter than the diaphragm 32. The sleeve member 60 has one end 60 </ b> A having a smaller diameter than the other part, and a recess is formed on each of the inner peripheral side and the outer peripheral side. One end 60 </ b> A is disposed outside the upper caulking ring 42, and engages the upper caulking ring 42 with a recess on the inner peripheral side. The other end 60B of the sleeve member 60 is disposed in the vicinity of the U-shaped portion 34 of the diaphragm 32 when neutral, and an opening 60K is formed inside the other end 60B.

  The other end 60B of the sleeve member 60 is curved outward in the radial direction, and the diaphragm 32 side is formed in an R shape.

  The sleeve member 60 is disposed so as to cover the outer periphery (side surface) of the diaphragm 32 when neutral. The diaphragm 32 can enter and exit from the lower opening 60K of the sleeve member 60. The sleeve member 60 is made of resin. Thus, by arranging the sleeve member 60 so as to cover the outer periphery of the diaphragm 32, the diaphragm 32 comes into contact with the inner wall of the sleeve member 60 when deforming according to the air pressure in the chamber chamber 44. Since the inner wall 60 is a smooth curved surface, wear of the diaphragm 32 due to sliding contact is suppressed.

  The air spring 10 is provided with a resin dust cover 50 formed in a substantially cylindrical shape. The dust cover 50 is provided with a connecting cylinder portion 52 fixed to the connected portion 22B of the chamber member 22 at the upper end portion, a shoulder portion 54 extending from the lower end portion of the connecting cylinder portion 52 to the outer peripheral side, and A cylindrical bellows portion 56 that extends downward from the lower end portion of the shoulder portion 54 and can be expanded and contracted along the swinging direction of the suspension arm 14 is integrally provided. The shoulder portion 54 is formed into a shape (tapered shape) that extends obliquely downward from the lower end portion of the connecting cylinder portion 52 toward the outer peripheral side as a whole.

  The connecting cylinder part 52 is formed in a cylindrical shape having a smaller diameter than that of the bellows part 56, and is fitted into the recess of the one end 60 </ b> A of the sleeve member 60. The dust cover 50 includes a fastening band 66 that is wound around the outer peripheral side of the connecting cylinder part 52, and the fastening band 66 is configured so that the one end 60 </ b> A of the connecting cylinder part 52 and the sleeve member 60 is entirely on the outer peripheral surface of the upper caulking ring 42. It is press-contacted over the circumference. Thereby, the connection cylinder part 52 and the sleeve member 60 are fixed to the outer peripheral side of the to-be-connected part 22B in the chamber member 22 through the one end part 32A and the upper caulking ring 42.

  A substantially cylindrical connecting lower end 58 is formed below the bellows portion 56 of the dust cover 50. The connecting lower end portion 58 is fitted and inserted on the outer peripheral side of the bracket 26, and a fastening band 68 is disposed on the outer periphery thereof, and is pressed and fixed to the bracket 26 side by the fastening band 68.

  The accordion portion 56 of the dust cover 50 is formed with a large number of fold lines extending in the circumferential direction, and these fold lines are arranged at a substantially constant pitch along the swinging direction of the suspension arm 14. In the bellows portion 56, the intermediate portion of the dust cover 50 is formed by being alternately bent toward the inner peripheral side and the outer peripheral side along a large number of bent line portions, and the angle of the bent portion is changed by using the bent line portion as a hinge. It can be easily expanded and contracted in the vertical direction. The dust cover 50 protects the operating portion of the air spring 10 from entering foreign matter from the outside.

  Here, the connecting cylinder part 52, the shoulder part 54, the bellows part 56, and the connecting lower end part 58 in the dust cover 50 are formed by blow molding using, for example, a polyolefin elastomer which is a relatively flexible resin material. (Blow molding). The molding material for the dust cover 50 may be other resin materials, rubber compositions, or the like as long as it is rich in flexibility and can be blow-molded even if it is not a polyolefin elastomer.

  Next, the operation of the air spring 10 according to the present embodiment configured as described above will be described.

  The air spring 10 is interposed between the vehicle body 15 and the suspension arm 14, thereby applying a spring reaction force corresponding to the air pressure in the chamber chamber 44 to the suspension arm 14. The spring reaction force supports a load input to the suspension arm 14 from the road surface side. That is, as shown in FIG. 2A, when the suspension arm 14 swings to the vehicle body side (bound direction X) due to the load from the road surface side, the air in the chamber chamber 44 is compressed by the piston member 24 and the air pressure is increased. The air pressure rises, and a load input from the road surface side through the suspension arm 14 is supported by the air pressure.

  At this time, since the piston member 24 moves to the inside of the sleeve member 60, the U-shaped portion 34 of the diaphragm 32 moves from the opening 60 </ b> K of the sleeve member 60 to the back side. In the dust cover 50, the bellows portion 56 is compressed to follow the relative movement between the chamber member 22 and the bracket 26. Subsequently, when the suspension arm 14 swings in the direction away from the vehicle body (rebound direction Y) and the piston member 24 moves to the outside of the sleeve member 60, the U-shaped portion 34 of the diaphragm 32 becomes the opening portion of the sleeve member 60. It is formed outside 60K. In this case, the dust cover 50 is extended to follow the relative movement between the chamber member 22 and the bracket 26.

  Thereafter, when the suspension arm 14 swings again toward the vehicle body side (bound direction X), the U-shaped portion 34 of the diaphragm 32 moves while the other end 60B of the sleeve member 60 and the diaphragm 32 rub against each other. In the present embodiment, since the other end 60B is curved outward and is formed in an R shape, wear due to rubbing between the diaphragm 32 and the other end 60B of the sleeve member 60 can be reduced. It is possible to suppress the life from being shortened.

  In the present embodiment, the other end 60B of the sleeve member 60 is curved outward to form an R shape to reduce the friction with the diaphragm 32. However, the other end of the sleeve member may have another configuration. it can.

  For example, as shown in FIG. 3, the other end 60C may be formed in a tapered shape having a large diameter toward the outside, or a round corner 60D may be formed at the other end as shown in FIG. Also good.

  In addition, as shown in FIG. 5, the friction between the diaphragm 32 and the sleeve member 60 can be reduced by attaching a round-cornered cover 60 </ b> E to the other end.

It is side surface sectional drawing which shows the structure of the suspension to which the air spring which concerns on embodiment of this invention was applied, and has shown the state which has a suspension arm in a neutral position. (A) is side surface sectional drawing of the air spring which concerns on embodiment of this invention when a suspension arm is rock | fluctuated in the bound direction, (B) is when a suspension arm is rock | fluctuated in the bound direction. It is side surface sectional drawing of the air spring which concerns on embodiment of this invention. It is side surface sectional drawing which shows the modification of the air spring which concerns on embodiment of this invention. It is side surface sectional drawing which shows the other modification of the air spring which concerns on embodiment of this invention. It is side surface sectional drawing which shows the other modification of the air spring which concerns on embodiment of this invention.

Explanation of symbols

14 Suspension arm 15 Car body 22 Chamber member 24 Piston member 28 Connected portion 29 Lower caulking ring 32 Diaphragm 32A One end portion 32B Other end portion 34 U-shaped portion 44 Chamber chamber 50 Dust cover 60E Cover 60 Sleeve member 60A One end 60K Opening portion 60D Round corner 60B The other end 60C The other end

Claims (4)

An air spring disposed between a first moving body and a second moving body that move relative to each other,
A chamber member attached to the first moving body;
A piston member attached to the second moving body;
A cylindrical chamber is formed with one end connected to the chamber member and the other end connected to the piston member to form a chamber chamber. The other end having a smaller diameter than the intermediate portion A diaphragm folded back into the cylinder as an inside-outside inversion state;
A cylindrical sleeve member having one end attached to the first moving body and the other end opened, and covering an outer periphery of the diaphragm;
With
An air spring in which a friction reducing portion for reducing friction with the diaphragm is formed at the other end of the sleeve member.   The air spring according to claim 1, wherein the friction reduction portion is formed by bending the other end of the sleeve member outward.   The air spring according to claim 1, wherein the friction reduction portion is formed with a rounded corner at the other end of the sleeve member.   The air spring according to claim 1, wherein the friction reduction portion is formed by attaching a rounded corner cover to the other end of the sleeve member.

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